Subcaliber adapter



Feb. 29, 1944. NELSQN I 2,342,684

SUB-CALIBER ADAPTER- Filed April 27, 1942 E1 an A -N'15nn Patented Feb. 29, 1944 Glen A. Nelson, United States Army, Camp San Luis Obispo, Calif.

Application April 27, 1942, Serial No. 440,583

(Granted under the act of March 3, 1883, as

amended April 30, 1928; 370 0. G. 757) 3 Claims.

The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a sub-caliber adapter which is insertable in the barrel bore of a gun and more particularly relates to a sub-caliber adapter for a mortar.

An object of this invention is to provide a subcaliber adapter for a mortar which may be inserted in the barrel of a standard mortar without injury of any kind to the barrel and so as to become part of the standard gun.

Another object of this invention is to provide a sub-caliber adapter for a standard mortar and yet the standard mortar may be aimed, fired, and adjusted in the conventional manner.

Another object of this invention is to provide a sub-caliber adapter for a conventional gun whereby projectiles may be fired from the conventional gun at ranges equal to approximately one-tenth the range of the standard weapon at a corresponding angle of elevation.

Another object of this invention is to provide a sub-caliber adapter in a standard mortar so as to stimulate interest, provide adequate fundamental training and give actual gun drill to the personnel of the standard mortar at low cost.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawing in which:

Figure 1 is a longitudinal section taken through the center of a preferred embodiment of my invention and shows in dotted lines M the barrel bore of a conventional mortar.

Figures 2, 3, 4, 5 and 6 are sectional views taken substantially on corresponding lines of Fig. 1.

Figure '7 is a side elevation of the firing pin plug shown in the assembly in Fig. 1.

Figure 8 is a side elevation of the firing pin of the assembly shown in Fig. 1.

The sub-caliber. adapter comprises the following essential elements: tube In, muzzle collar ll having the leather ring bufier llb thereon, 'base cap l2 having leather buffer ring lfld thereon, firing pin plug l3, and firing pin it. The outside diameters of muzzle collar ll andbase cap l2 with corresponding buffers llb, l2d thereon are substantially equal to the inside bore diameter of a standard mortar. Tube l0 has a length substantially equal to the length of the barrel of the standard mortar. The muzzle collar l I and base cap l2 thus snugly and resiliently abut the inner bore of the standard gun and preferably those parts are made of or lined with leather or other similar resilient material. The bottom end of the adapter in Fig. 1 is assembled in the following manner: firing pin plug l 3 is inserted in the base cap hollow portion lZb with shoulder 30 in abutting relationship to the end of tube l0, and set screws Ilia engage tube I 0 whereby the firing pin plug is retained in the base cap hollow portion I217. The firingpin plug l3 as shown in Fig. '7 has an axially extending hole l3a for the reception of pointed portion I la of firing pin l4 and also a screw threaded portion l3b for engagement with a corresponding screw threaded portion l lb of the firing pin. The firing pin it is conveniently inserted in the firing pin plug l3 through axially extending hole I20 in the base cap l2, and, of course, the firing pin may be conveniently removed through hole I20 without disassembling the firing pin plug from tube Ill.

The upper end of the sub-caliber adapter shown in Fig. 1 is assembled by inserting tube l0 in corresponding hollow portion No of the muzzle collar l l and then fastening the tube in place by means similar to set screws Ila.

It is seen that the pointed portion of firing pin l4 projects through and is partially protected by snugly fitting firing pin plug l3 so that when a mortar projectile which may be similar to the one described in my copending application, Serial No. 440,584, filed April 27, 1942, is dropped into tube Ill the primer of the projectile is detonated upon striking pin l4.

Also, it is noted that the base cap I 2 and muzzle collar ll are made substantially resilient by the resilient rings l2d, l lb, respectively, but it is understood that means other than of ring-shaped structure may be employed and the muzzle collar l l and base cap l2 may be of resilient material such as leather.

I claim:

1. A sub-caliber adapter for a standard gun, comprising a tube having a length substantially that of the gun barrel, a base cap mounted on one end of the tube and a muzzle collar on the other, each being provided exteriorly with packing means for engagement with the inner periphery of the barrel, a firing pin plug having a shoulder, said base cap having a central recess in which the plug is seated, said tube having its adjacent end seated in the base of the cap recess in abutting relationship to the firing pin plug shoulder, means carried by the basecap for locking the tube to the cap, a firing pin carried by the plug, the plug having a portion partially surrounding the firing pin and in protective relation thereto.

2. A sub-caliber adapter for a standard gun, comprising a tube having a length substantially that, of, the gun barrel, a muzzle collar mounted on one end of the tube and snugly engaging the inner periphery of the barrel, a base can mounted on the other end of the tube and provided exteriorly with packing means for engagement with the inner periphery of the barrel, 2. firing pin plug having a shoulder, said base cap having a central recess in which the plug is seated, said tube having its adjacent end seated in the base cap recess in abutting relationship to the firing pin plug shoulder, means carried by the base cap for locking the tube to the cap, and a firing pin carried by the plug.

3. The invention asclaimed'in claim 1 characterized in that there is an axial opening in the base of the cap for insertion and removal of the firing pin.

GLEN A. NELSON. 

